exam 3 quizzes

The following are specific events in the relaxation of a muscle fiber. Choose the order in which they occur. 1. Calcium ions are pumped back into the sarcoplasmic reticulum (SR) 2. Acetylcholinesterase degrades remaining acetylcholine (ACh) 3. Troponin and tropomyosin block actin active sites 4. Sarcolemma returns to resting membrane potential

2,4,1,3

The Na+/K+ ATPase pumps move _____________ sodium __________ the cell and ____________ potassium ___________ the cell with each ATP that is hydrolyzed.

3, out of, 2, into

During sarcomere contraction, the A and H bands narrow but the I band remains the same width.

False

In a muscle fiber, high calcium levels within the sarcoplasm will cause muscle fiber relaxation.

False

Temporal summation of graded potentials occurs when several postsynaptic potentials arrive close to the same time from several different presynaptic neurons.

False

The basal nuclei, located within the diencephalon of the brain, is composed of white matter

False

The large ventral (anterior) rami of spinal nerves innervate the skin and muscles of the back.

False

The patellar reflex is a contralateral, polysynaptic somatic reflex.

False

The substantia nigra is a darkly pigmented region of the midbrain whose neurons release the neurotransmitter serotonin.

False

The hormone _______________ is produced by the pineal gland of the diencephalon.

Melatonin

Regardless of whether its skeletal, cardiac or smooth muscle cell is called a/an

Myocyte

The myofibril is the contractile organelle of skeletal muscle, and the ____________ is the functional unit

Sacromere

The final relay point for most ascending sensory information (but not olfactory information) that will be projected to the higher centers of the cortex is the ______________.

Thalamus

A _________ consists of one T tubule and a pair of terminal cisterns (the enlarged tubules of the sarcoplasmic reticulum).

Triad

An IPSP produces a graded hyperpolarization at the postsynaptic membrane.

True

Bundles of myelinated axons (also known as a fascicle) are enclosed in a connective tissue membrane called the perineurium.

True

Characteristics of electrical synapses include speedy communication and bidirectional flow of ions.

True

Hyperpolarization is an increase in the membrane potential of a neuron (the interior of the cell becomes more negative), which reduces the probability of producing a action potential.

True

Motor nerve axons branch out to innervate each and every skeletal muscle fiber.

True

Nebulin is a non-elastic protein that anchors the thin filaments to the Z discs.

True

Skeletal muscle is voluntary, striated, multinucleate and organized into parallel fibers.

True

T tubules are narrow tubes that are continuous with the sarcolemma and filled with interstitial (extracellular) fluid.

True

The limbic system is a functional grouping of structures that plays a role in establishing emotional states and facilitating memory storage and retrieval.

True

The __________ refractory period occurs when Na+ channels are either open or inactivated, before their return to their resting state. No Na+ can cross the membrane during this time.

absolute

Troponin has three subunits, and so three different things can bind to it. Name ONE of the things that binds to a troponin subunit

actin

Which of the following choices is TRUE regarding an action potential in a muscle fiber? opening of voltage gated calcium channels in the motor end plate directly causes depolarization of the cell to threshold potassium influx into the cell is responsible for the depolarization phase action potentials propagate across the sarcolemma and down every T-tubule voltage gated sodium channels close when the membrane potential reaches approximately -30 mV

action potentials propagate across the sarcolemma and down every T-tubule

Which of these is controlled by the nervous system? skeletal muscle movement heart rate ventilation rate all of these are controlled by the nervous system thermoregulation

all of these are controlled by nervous system

z disc

anchors the thin filaments and titin strands; marks the end of the sacromere

thick filaments

attached to the M-line; extend the entire length of the A-band

All of the following are TRUE regarding neurotransmitters except c. Neurotransmitters can be taken up by other cells in the vicinity of the synapse a. Neurotransmitters can be degraded by enzymes b. Removal of neurotransmitters from the synaptic cleft is not essential d. Neurotransmitters can diffuse away from the synaptic cleft

b. Removal of neurotransmitters from the synaptic cleft is not essential

Which organs or tissues are activated, increased or receive increased blood flow during a sympathetic nervous response? Select all that apply!

lipolysis (catabolism occurring from adipocytes) production of hormones - epinephrine and norepinephrine pupil size skeletal muscle of limbs heart rate sweat glands

M line

made from protein myomesin; center of each sacromere

Which neuroglia (glial cell) is responsible for "scanning" their area of the CNS and can develop phagocytic properties if they encounter an invader or cellular debris?

microglia

The ___________ nerve innervates the diaphragm.

phrenic

somatosensory association area

preforms further processing of information from the primary sensory cortex

gustatory cortex

receives sensory information from taste receptors

primary somatosensory cortex

receives sensory information from touch, temperature, pressure receptors

zone of overlap

region where both thick and thin filaments exist

The return of the sarcolemma to resting electrical conditions by the efflux (exit) of K+ through open voltage-gated channels is called _____________________.

repolarization

Folia

ridges on cortical surfaces

association fibers

short fibers connecting one cerebral gyrus with another

The somatic sensory division of the PNS is responsible for transmitting information from _________ to the _________.

skeletal muscles / brain

vermis

structures that connect the let and right hemisphere

H-zone

surrounds the M-line ; lighter mid-region where thin and thick filaments do NOT overlap

Resting membrane potential in a skeletal muscle cell is maintained primarily by ________.

the Na/K pumps

A toxin that increases the release of neurotransmitter at synapses or the prevents the closing of postsynaptic sodium channels would lead to the overstimulation of the postsynaptic neuron.

true

Acetylcholinesterase promotes muscle relaxation by breaking down acetylcholine

true

Continuous conduction of action potentials is slower and less efficient than saltatory conduction. One of the reasons for this is that more membrane surface area must be depolarized during continuous conduction, which requires expending more ATP to restore resting conditions.

true

Each skeletal muscle cell runs the length of the entire muscle and is attached to the tendons at each end using connective tissue membranes.

true

Excitation-contraction coupling refers to all of the events happening between generation of an action potential in the sarcolemma and the start of the muscle contraction.

true

The amplitude (size) of a graded potential is determined by the stimulus strength, in other words, by the amount of neurotransmitter released at the synapse.

true

The demand for ATP is so high in a contracting muscle, it would be impossible to have all the necessary energy available as ATP before a contraction begins

true

When calcium enters into a neuron's axon terminal through voltage-gated channels in the cell membrane, acetylcholine is released from the synaptic knob/terminus into the synaptic cleft.

true

The visual association area allows you to

understand that it's your mother's face, not some other person

The ________________(give name not number) nerve is the exception to the rule that cranial nerves only innervate structures in the head and neck.

vagus

_______________ - gated channels open and close in response to changes in membrane potential.

voltage

Which of the following are NOT correctly paired? All of the above are correctly paired synaptic cleft/gap between neuron and muscle cell end plate potential / same as a local or graded potential voltage-gated K+ channel/receptor for acetylcholine chemically-gated sodium channels / depolarize motor end plate when open

voltage-gated K+ channel / receptor for acetylcholine

Electrons that are removed from fuel molecules during aerobic catabolism are transferred to oxygen, producing ________________.

water

arbor vitae

white matter

commissual fibers

communication between cerebral hemispheres

peduncles

connection to brain stem

In a _________________ neural circuit, several neurons relay information to a single neuron.

converging

primary motor cortex

directs voluntary movement

Which meningeal layer creates the falx cerebri?

dura mater

Which of the following is NOT a function of skeletal muscle? a. produce skeletal movement e. control pupil size c. control posture and body position d. assist with stabilizing joints b. generation of body heat

e. control pupil size

thin filaments

extended from each Z-disc to the each side's H-zone , but not into the H-zone

"Type A" axons are small, unmyelinated fibers that conduct impulses at approximately 2 meters per second.

false

Glycolysis is the aerobic breakdown of glucose to produce two molecules of pyruvic acid that occurs in the mitochondria of a muscle cell

false

The effect of a neurotransmitter (excitatory versus inhibitory) on the postsynaptic membrane depends on the properties of the neurotransmitter, not on the properties of the receptor.

false

The perimysium surrounds the entire muscle, the epimysium surrounds each fascicle, and the endomysium surrounds each individual muscle fiber.

false

olfactory cortex

found in temporal lobe

visual cortex

found in the occipital lobe

Each posterior spinal nerve root has an enlargement, called the posterior (dorsal) root ___________, which contains the cell bodies of __________ neurons, while the anterior root of each spinal nerve contains the axons of ________ neurons.

ganglion, sensory, motor

primary sensory cortex

in the postcentral gyrus

primary motor cortex

in the precentranl gyrus

__________________ corpuscles are spiral-shaped discs that adapt quickly to deep pressures and vibrations.

lamellated

projection fibers

link the cerebral cortex with other regions of the brain and spinal cord

Which of the following is FALSE? Graded potentials cannot increase the polarity of a cell membrane. They're only able to depolarize the membrane in order to attempt to reach threshold. Different voltages across the cell membrane are responsible for opening or closing various ion channels, allowing their ions to cross into the ECF or cytosol. Threshold potential (-55mV) represents the level of membrane graded/local depolarization that would be sufficient to trigger the opening of voltage regulated sodium channels. No matter how strong or weak the initial stimulus, once threshold is reached, an action potential will occur- and all action potentials have the same magnitude.

Graded potentials cannot increase the polarity of a cell membrane. They're only able to depolarize the membrane in order to attempt to reach threshold.

Which of the following is NOT true? The sacral plexus is formed by the anterior rami of L4-L5 and S1-S4, and gives rise to the largest nerve in the body, the sciatic nerve. Organs that are innervated by the cervical plexus will demonstrate referred pain in the thoracic and lumbar areas of the torso. The ulnar nerve is the true "funny bone." The tibial nerve is the largest branch of the sciatic nerve.

Organs that are innervated by the cervical plexus will demonstrate referred pain in the thoracic and lumbar areas of the torso.

Which of the following is NOT part of the brain stem? a. cerebellum b. pons c. midbrain d. medulla oblongata e. all of the above are part of the brain stem

a. cerebellum

Which of the following is NOT a function of the hypothalamus? a. conscious control of skeletal muscle movement b. regulation of body temperature c. secretion of hormones from the pituitary gland d. coordination of activities of the endocrine and nervous systems e. regulation of thirst and hunger

a. conscious control of skeletal muscle

Which of the following is FALSE? a. Broca's area regulates the tongue movements needed for normal speech. b. The parietal association area is responsible for an individual's personality c. The cerebellum integrates motor error into current motor programs d. An individual with a damaged speech center can make sounds but not coherent sentences. e. Wernicke's area is involved in understanding written and spoken language.

b. The parietal association area is responsible for an individual's personality

Which of the following is FALSE? a. an entire muscle is made up of multiple fascicles d. myofilaments are the thick and thin filaments of the sarcomere c. each muscle fiber is wrapped in sarcoplasmic reticulum b. myofilaments are made of bundles of myofibrils e. the thick filaments are composed primarily of the protein myosin and the thin composed of actin

b. myofilaments are made of bundles of myofibrils

Which of the following is NOT regulated by centers in the medulla oblongata? a. swallowing b. sleeping c. sneezing d. vomiting e. coughing

b. sleeping

Which of the following is FALSE? a. K+ crosses plasma membranes more easily than Na+ b. There are more negatively charged proteins inside cells than outside d. A gradient in the ion concentrations represents potential energy e. none of the above are false c. Whenever positive and negative ions are separated from each other, a potential difference exists

none are false

________ are responsible for myelination in the CNS, while _________ are responsible for myelination in the PNS.

oligodendrocytes / Schwann cells